Stabilization of organic compounds



Patented Oct. 19, 1954 2,692,202 STABILIZATION OF ORGANIC COMPOUNDS Joseph A. Chenicek, Bensenville, and Ralph B. Thompson, Hinsdale, Ill., assignors to Universal Oil Products Company,

ration of Delaware Chicago, 111., a corpo- No Drawing. Application May 31, 1951,

Serial No. 229,266

24 Claims. (Cl. 99-163) This application is a continuation-in-part of our copending application Serial No. 4,079 filed January 23, 1948, now abandoned.

This invention relates to the stabilization of organic compounds which tend to deteriorate in storage or in use due to oxidation reactions.

Various organic compounds are unstable in storage or during treatment and form undesirable gums, undergo discoloration, form sludges or otherwise deteriorate due to oxidation, polymerization or other undesired reactions. Included among the organic compounds which undergo such deterioration and which are. intended for treatment according to the present invention are gasoline, diesel oil, mineral oil, lubricating oil, fuel oil, drying oil, greases, edible fats and oils, acetylenes and particularly vinyl acetylene, butadiene, isoprene, styrene and other vinyl aromatics, various unsaturated alcohols, acids, ketones, etc.

The invention is particularly applicable to the stabilization of unsaturated gasolines and particularly cracked and polymer gasolines. In storage or during treatment these unsaturated gasolines tend to form undesirable gums. The invention is also applicable to the treatment of aviation gasolines which, tend to undergo deterioration due to the addition of tetraethyl lead fluid or due to other components in the gasoline.

The invention is also particularly applicable to the stabilization of edible fats and oils which generally are of animal or vegetable origin and which tend to become rancid, especially during long periods of storage prior to use. Typical representatives of these edible fats and oils include linseed oil, menhaden oil, cod liver oil, castor oil, olive oil, rapeseed oil, coconut oil, palm oil, corn oil, sesame oil, peanut oil, babassu oil, butter, fat, lard, beef ta low, etc. It is understood that other oils and fats may be treated within the scope of the present invention, including oils and fats which have previouslybeen sub.-

jected to various treatments, such as blowing with air, heat treatment, etc.

In another embodiment the present invention is particularly applicable to the treatment of crops by dusting or spraying in order to preserve food accessory factors such as carotene, vitamins, various fatty acids, alcohols, etc.

In one embodiment the present invention relates to a method of stabilizingan organic material subject to oxidative deterioration which com- 1 prises adding thereto a monoalkyl ether of a dihydroxydior tetrahydronaphthalene.

In another embodiment the present invention relates to a method of stabilizing an organic material subject to oxidative deterioration which comprises adding thereto a monoalkyl ether of a 1,4-dihydroxydior tetrahydronaphthalene.

In a specific embodiment the present invention relates to a method of stabilizing motor fuel normally tending to deteriorate in storage which comprises adding thereto from about 0.001% to about 0.5% by weight of l-hydroxy-4-methoxy- 5,8-dihydronaphthalene.

In another specific embodiment the present invention relates to a method of stabilizing edible fats and oils against rancidity which comprises adding thereto from about 0.001% to about 0.5% by weight of 1-hydroxy-4-methoxy-7-methyl-5,8- dihydronaphthalene.

In another embodiment the present invention relates to motor fuel normally tending to deteriorate in storage containing, as an inhibitor for said deterioration, a small amount of a l-hydroxy-4-alkoxy-5,8-dihydronaphthalene or a 1- hydroxy-4-alkoxy-5,6,7,8-tetrahydronaphthalene.

In another embodiment the present invention relates to edible fats and oils normally tending to become rancid containing a l-hydroxy-ialkoxy-5,8-dihydronaphthalene or a l-hydroxy- -alkoxy-5,6,7,8-tetrahydronaphthalene in an amount sufiicient to retard rancidity development.

In accordance with the invention, stabilization of unstable organic compounds is effected by adding thereto a small amount of a monoalkyl ether of dihydroxy-5,8-dihydronaphthalene or of dihydroxy-5,6,7,8-tetrahydronaphthalene. It has been found that these monoalkyl ethers unexpectedly are of high potency in preventing deterioration of organic compounds. As will be shown in the following examples, these monoalkyl ethers exhibit extremely high potency in contrast to the low and in many cases no inhibitor potency for the corresponding dihydroxynaphthalenes, monoalkyl ethers of dihydroxynaphthalenes, dihydroxy-hydronaphthalenes and the dialkyl ethers of dihydroxynaphthalenes and dihydroxyhydronaphthalenes. These extremely high potencies exhibited by the monoalkyl ethers of the dihydroxy-hydronaphthalenes are surprising 'in view of the fact that the compounds as mentioned above, which might be considered somewhat similar to the compounds of the present invention, either are of low efiect or substantially of no effect as inhibitors, as well as the fact that the etheriflcation of the monocyclic dihydroxyphenols, as will be shown in the following examples, actually decreases the inhibitor potency. Therefore, in the absence of the teachings of the present application, one would be lead away from the etherification of the dihydroxynaphthalene in a desire to obtain active inhibitor. Furthermore, it has been found that these monoalkyl ethers are Q 1.) considerably more soluble in organic compounds than the corresponding dihydroxynaphthalene and, therefore, these ether compounds are particularly suitable for use as inhibitors The preferred inhibitors of the present invem tion may be represented by the following general structures:

Structure I illustrates l-hydrogy: 4-all;o;ry.-5 dihydronaphthalene and structure II illustrates 1 hydroxy 4 alkoxy 5,6,'7,8 tetrahydronaphthalene.

Referring to the general structure illustrated v H ompr e hy ro en and. compr se an alkyl radical preferably, containing from 1 tov about 8 carbon atoms and therefore. includes alkyl groups such as methyl, ethyl, propyl, butyl, amyl, hexyl, heptyl and ocllyl. Still more, par: ticularly. R preferably comprises an alkyl group containing from I to l carbon atoms and includes such groups as ethyl, methyl, propyl. and butyl. This is particularly true when l. or both of the rings are. substituted with alkyl groups in the manner. to be hereinafterset forth, in. order that the. total number of. carbon. atoms'does not exceed about 25. and preferably 2.0.

As hereinbefore set forth, one or-both of. the rings may be, substituted with alkyl grou or ro ps. Preferably each alkyl oup. hould not contain more than about. acarbon atoms in order that the total number. oft carbon atoms in the, in-. hibitor does not exceed about 25 and still more preferably. does not exceed about 20, Preferred alkyl ps. inc ude. ethyl. me yl, prop l, tertiary, butyl, and tertiary amyl radicals.

Preferred inhibitors of the. present, invention include 1 hydroxyl-methoxy 5,8-dihydronaphthalene, 1-hydroxy-4-ethoxy-5,8 dihydronaphr thalene, 1 hydroxy. 4. propoxyk 5,8 1.61 37:- dronaphthalene, 1 hydroxy. 4 butoxy. 5.,8- dihy r naph lene, 1 hy roxy 111313110X),- 'L -.m. hy 5,8 ihydrnaphtha1ene, L 1 hrdroxy 4 1 ethoxy '7 methyl 5,8 dihydronaphthalene, 1 hydroxy, l propogryv 7- met yl. 5,8; d hydronaph halene, 1 hydroxy 44.: ut xy. '7. methyl. '7 5,8 -.d h dronaphtha1ene, 1. xy methoxy, 15,7. dimethyl 15,8...- hydrona h halen 1 hydroxy. 4. GIZhOXYr' ,7 me. hy1 5,8 dihvdronaphthalene, 1 by,- droxy, 'r 4. -.pr po.xy 5,7. -,.dim thyl 5,8 dihyr ronapht a ene, hydroxy. 4. u y. 5. d e hy 15,8. -.dihyd.r. naphtha ene, 1 -.hydrox 4. e xy 5,618 tetrahydronaphthalene, 1-

hyd xy. t oxy 515, 38. tetrahydronapnthalene, 1 hydroxy 4 propQ yv .5,6,7,8.- tetrahs ro aphtha e, 1 hyd o e uto y 5,6,'7,3 t etrahydronaphthalene, 1 -.hydroxy 4.- eth x met ,651 -.tetrahrd na hhalene 1 -.h r iy 1% e hoxa 1.7-. meth l: 5,6173. -.t. t ahyd a ht 1ene, budroxv 4..- pr o yl m t yl 55,18 t trahydronaphr t e e ydr y-z e u xy 17-. -.methy1- 5.,6,7,fi-tetrahydronaphthal ne. lhydroxy 4rm x 5,7 -.dmet y1 16 718; tetrahydror naphthalene, 1 e hydroxy l; ethoxy. 5-,7 dim t yl 5, 7-,8 -.tetr, hyd o a htha1ene, -..hy.- d xy p oxyt 5, dimethyl -1 536, r tr h d onapht a e e a d I hydroxy. 4.- butoxy 5,7 dimethyl- 5,6,7,8 tetrahydronaphhalene,

It will be noted that the preferred inhibitors include the l-hydroxyl-alkoxy-diand tetrahydronaphthalenes, as well as those in which an alkvl group or groups are attached in the 5 or 5 and '7' positions. While, these, are the preferred compounds it is understood that substitution of alkyl group or groups in other positions on either or both of the rings are included Within the scope. of the present invention.

It is understood that the inhibitors of the present invention may comprise the specific compounds named herein in admixture with various isomers thereof.- For example, in the dihydrocorn" oundsf'the: isomers may comprise corresponding compounds in which the double bond hasshifted from the 6-7 position to the 5-6 or L8 positions, and/ or those in which the hydroxy andalkoxy groups have interchanged positions with. respect to an allgyl group. In the tetrahyo. compounds, the isomers" will be r t latter The inhibitors of the present invention may be p e a ed uit man e I I! b rt ed of preparing 1-hydroxy t-methoXy dihydronaph thalene, butad iene. is reacted with p -b enzoquinone. The p-b 'nzoquinone is preferably dis s'olved in a suitable or anic solvent such as alco hol, benzene, toluene; etc. The reaction readily pro eds t om tem era r w h. e. e e fiipii d he A er, t e reac on ha een o pleted' h 'bro uri l i d by etaliat on rbit i organic sol ats and then 'is' dissolved in acetic a i nd, a. w dropsv dfdb m were added't o 'efie'ct isomerization to the dih'y drow aromatic structure." The product may be re.- crysta i zed from rganic: solvents and then reacted with dimethylsulfate'to form the desired ether. The monoether is separated byv extract ing with Claisen solution and then is purified. by distillationund er vacuum, the thyl ether is'jdesnedjdiethyl sulfate is. used. instead of di-. methyl sulfate, Similarlyfwhen. l-hydroxy l; methoxy-fl methyl-dihydronaphthalene' is 'de; sired, isoprene is used in place of"buta'diene, v/ rlentne 5;; r ll-substituted;compoundiside for, 2 -rnethyl p'entadiene isutiliized inits p eDv anon, 4 methoxy e 5,6,'7,8 tetrahydrof- 1 'ydroxy I naphthalene mayv be prepared by dissolving} 1,4-

di W-ififim oe pli a in. a u a l solvent, such as ethyl. acetate; and reducingwith hydrogen in the presence. of a suitable catalyst such as paladium on calcium carbonate," The des ed ether may. be formed by. reacting with dimethyl sulfate," diethyl sulfate, eito'fin the manner hereinbe fore set forth,

c Sta t one, aiterlwhich theproduct may be P r to. Water, ext ac ed. fi w th r a i solvents and thenwith (ilaisensolution and finaly e am acfu m "Ifhe inhibitor o'f'the present invention is genrel im t9; Qr e'mo' .elter' a l b iii ainb i ft qis s.- ea .by em and e e lly Wi hi the range r from. about .0 1% to. about. 0.5%. when used; in gasoline, itis. understood that the inhibitonmavbeused in conjunction with various dyes, synergists, metal deactivators, antiknock 1-hydroxy-4-methoxy5,6,7,8-tetrahydronaphthalene.

set forth.

EXAMPLE I The following runs were made with a lard which had a normal stability period of 3 hours as determined by the Swift test. This test is described in detail in the article by A. E. King, H. L. Roschen and W. H. Irwin, which appeared in the Oil and Soap, vol. X, No. 6, pages 105 to 109 (1933). In general, this test comprises bubbling air through a sample of the lard and reporting the number of hours until the lard develops a peroxide value of 20.

Inhibitor in concentrations of 0.02% by weight was added to difierent samples of the lard and ave the results as shown in Table 1.

Table 1 Stability Period, Hours Inhibitor l-hydroxy-4-methoxy-5,S-dihydronaphthalene 1-hydroxy-4-ethoxy-5,8-dihydronaphthalene 1-hydroxy-4-methoxy-7-methyl-5,8-dihydronaphthalene l-hydroxy-4-ethoxy-7-methyl-5,S-dihydronaphthalene.

l-hydrxy-4-ethoXy-5, 6, 7,8-tetrahydronaphthalene l-hydroxy 4 methoxy 7 meth yl 5,6,7,8 tetrahydronaphthalene Above compound butylated l-lgdlroxyi-ethoxy -7-methyl 5, 6, 7,8 -tetrahydronap a cue l-hydroxy 4 niethoxy 5,7 dimethyl 5,6, 7, 8 tetrahydronaphthalene l-hydroxy -4-ethoxy 5,7 dimethyl 5, 6, 7,8 tetrahydronaphthalene It will be noted from the data in the above table that the various inhibitors of the present invention considerably increased the stability period of the lard.

EXAIWPLE II The following tests were made with a Pennsylvania cracked gasoline which had an uninhibited induction period of 100 minutes. 0.025 by weight of inhibitor was added to difierent samples of the gasoline and gave the results as shown in Table 2.

Table 2 Induction Inhibitor Period, Minutes l-hydroxy-4-methoxy-5,8-dihydronaphthalene 880 l-hydroxy-i-ethoxy-5,8-dihydronaphthalene 95o '1hydroxy-4-methoxy-7-methyl-5,8-dihydronaphthalene. 790 1-hydroxy-4-ethoxy-7-methyl-5,8-dihydronaphth alene 865 1 hydroxy 4 methoxy 5,7 dimethyl 5,8 dihydronaphthalene 805 l hydroxy 4 ethoxy 5,7 diniethyl 5,8 dihydronaphthalene 810 l-hydroxy-4-methoxy-5,6,7,8-tetrahydronaphthalene. 885 1-hydroxy-4ethoxy-5,6,7,B-tetrahydronaphthalene 890 1 hydroxy 4 methoxy 7 methyl 6,6,7,8 tetrahydronaphthalene 790 1 hydroxy 4 ethoxy 7 methyl 5,6,7,8 tetrahydronaphthalene 810 1 hydroxy 4 methoxy dimethyl 5,6,7 8 tetrahydronaphthalene 855 1 hydroxy 4 ethoxy 5,7 dimethyl 5, 6,7,8 tetrahydronaphthalene 800 It will be noted from the data in'the above 6 t table thatthe inhibitors of the present invention considerably increased the induction periods of the gasoline.

EXAMPLE III For comparative purposes, 0.025% by weight of a corresponding dihydroxy-5,8-dihydronaphthalene and of a corresponding dimethoxy-dihydronaphthalene were tested in other samples of the cracked gasoline used in Example II. The results of these tests are shown in Table 3.

Table 3 Induction Inhibitor Period,

Minutes 1, 4-dihydroxy-5,7-di1nethyl5,8dihydronaphthalene 1, 4 dimethoxy7methyl-5,8dihydronaphthalene 100 It will be noted that the dihydroxynaphthalene and the dimethoxynaphthalene had no effect at all in improving the induction period of the cracked gasoline. On the other hand, the corresponding 1-hydroxy-4-methoxy-5,7-dimethyl- 5,8-dihydronaphthalene increased the induction period from 100 to 805 minutes and the corresponding 1-hydroxy-4-methoxy-7-methyl-5,8-dihydronaphthalene increased the induction period from 100 to 790 minutes.

EXAIVDPLE IV As hereinbefore set forth the monoalkyl ethers of the dihydroxy-hydronaphthaienes are of unexpectedly higher potency than the corresponding dihydroxynaphthalenes, the dihydroxy-hydronaphthalenes, the monoalkyl ethers of dihydroxynaphthalenes, the dialkyl ethers of dihydroxynaphthalenes and the dialkyl ethers of dihydroxyhydronaphthalenes. Table 4 shows the results obtained inthe stabilization of lard when using dihydroxynaphthalenes and dihydroxy-tetrahydronaphthalenes, as well as the results obtained when using the monoalkyl ethers of the hydronaphthalenes of the present invention.

Table 4 Stability Period, Hours Compound 3%. {Dihydroxynaphthalenesz less than 22. less than 18.

less than 20.

less than 21.

1,4-dihydro xynaphthalene 2-methyl-l,4-dihydroxynaphthalene- Dihydroxy-tetrahydronaphthalenes:

1,4-dihydroxy 5,6,7,8 tetrahydronaphthalene.

1,4-dihydroxy 7 methyl 5,6,7,8 tetrahydronaphthalene.

l, 4-dihydroxy-5,7 -din1ethyl 5,6,7,8 -tetrahydronaphthalene.

Monoalkyl ethers of dihydronaphthalene:

1-hydroxy-4-methoxy-5,8-dihydro -naphthalene.

l-hydroxy-4-ethoxy-5,8-dih ydro-naphthalene.

Lhydroxy-A-methoxy- 7 -1:nethy1 5 ,8 di

hydronaphthalene.

l-hydroxy-4-ethoxy-7-methyl 5,8 dihydronaphthalene.

Monoalkyl ethers of tetrahydronaphthalene:

l-hydroxy 4 methoxy 5,6,7,8 tetrahydronaphthalene.

l-hydroxy 4-ethoxy- 5,6, 7,8 tetrahydronaphthalene.

l-hydroxy- 4-methoxy-7-methyl-5,6,7,8-

tetrahydronaphthalene.

l-hydroxy 4 methox'y 5,7 dimethyl- 5, 6,7, S-tetrahydronaphthalene.

The reason that the stability period in hours is reported as less than a given number or as a range of two numbers is because the sample reached a peroxide value of 20 during the night,

at. which t me an. o erator was not nresontto W QEQ 7 1. .8.39 MH Y' ealqill a.

It will be noted that dihydroxynaphthalene or dihydroxy-tetrahydronaphthaiene, as well as alkylated derivatiyes thereof, as represented by classes 2 and 3, stabilized the lard for periods of less than 22 hours. In contrast thereto inhibitors prepared in accordance with the present invention, as represented by classes 4 and increased the stability period to over 36 hours as shown by the data 'in' the above table.

Table 4 represents. the. results obtained in the stabilization of lard using the various compounds setf orth above, as well as the monoalkyl ethers of the dihydroxy-hydronapththalenes of the present invention. The lard used was the same as that used in Example 1, and the various compounds were used in the same concentration of 0.02% by weight.

EXAMPLE V The ollow d a re. bta n d n he s abiz ion o alo d aving, a ormal st bilit p iod o hou n om are th s t ob n d y the use of 1-hydroxy-4-ethoxy-7-methyl-5,8-dihydron p ih w t he resul s obta ned hen s ng i rd h dr xli mfi i y r 3- 1 2hha n Th e o po n s w re. used n. a co centration of, 0.02 by weight.

It will be noted that the monoalkyl ether compound resulted in a stability period of greater than three times that obtained by the corresponding dihydroxy compound.

This example shows a similar comparison as shown in Examples IV and V using these inhibitors in cracked gasoline. The gasoline used in this example was the same as that used in Example II and the compounds similarly were used in a concentration of 0.025% by weight.

Table 6 Induc- No. Compound g g Minutes 9 None 100 l0. Dihydroxynaphthalene: Z-IDBlJhYPlu i-di- 80 hydroxynaphthalene. 11..." Dihydroxy-dihydronaphthalene: 1,4-(1ihydroxy- 100 7-inethyl-5',S-dihydronaphthalene. 12... Monoalkyl ether of dihydroxynaphthalene: 315

1-hydroxy-2-methy1-4-methoxy naphthalene. l3 Dialkyl ether dihydroxynaphthalene: 125

2-methyl-l,tdimethoxynaphthalene. 14 Dialkyl ether of dihydroxy dihydronaphthalene: 100

.11 ,4-dimethoxy-7-incthy1-5,8-dihydronaphthaene. Monoalkyl ethers of dihydronaphthalenes:

' 1-iydroi3*-4-methoxy-5,8-dihydronaphtha- 880 one. l-hydroXyA-ethoXy-aS-dihydronaphthalene 950 l-hydroxy-4-rnethoxy-7-mcthyl-5;8-dihydro- 790 naphthalene. l-hydroxy-4-ethoxy-7--methy1-5;8-dihydro 865 naphthalene. Monoalkyl ethers of tetrahydronaphthalene: hy o 3 s:- l 7 8.- e m .1 lm-. 885 l6..... naphthalene.

r y wz w ifi'bifl i e wdro' naphthalene In he i re of b evity. o l p es ntative compou s a e p r ed for the va ous classes in the above table. These results are typical of those obta nable w th com unds n t es classes.

In contrast to the poor results obtained with compound o ass s 0 to 1 c si xc ptional y high nhibitor poteno s r ob n d w th th compounds of t e present app cation a represented by compounds of classes L5 and 16. a more. specifi om a son, te part cu a the results obta ned. with compounds o lasses 11 and 14 as compared to the results obtained with the third compound or; class 15 wherein the former compoun s how no nhibi o p t ncy a h la ter comp nd shows a igh p tency,

From the data heretofore presented, it is noted that the monoalkyl ethers of dihydroxy-hydronaphthalenes are of unexpectedly high potency for use as inhibitors in the stabilization of organic compounds. These high potencies are all the more surprising because etherification of the dihydroxy-monocyclic aromatic compounds, serves to decrease the inhibitor potency in contrast to the high increase obtained by etherification of the polycyclic compounds. Table '7 presents data on the results obtained when using hydroquinone, as representative of the dihydroxymonocyclic aromatic compounds, and when using ethers of hydroquinone. These tests were made using lard which had a normal stability period of 1% hours. The compounds in these tests, were utilized in an amount of 0.005 by Weight,

Table 7 Stability No. Compound Period,

Hours 17 None 1% l8. Hydroquinonc 25 Hydroquinone mon ethyletheix 6 Hydroquinone monoethylether 7 It will be noted that converting hydroquinone tothe. ether considerably reduced the inhibitor potency of' the compound. In contrast to this, it will be noted from the data presented.- in Examples IV, V and VI that converting dihydroXy-hydron ph ha ene. to the mon ho onsiderablyr ascd bo inhibito r not norr As her inbcforese Q h the iBl: 76 1 is s p sin n v ewthe iormerrosul W 81 cla m as ourn e tion;

1. A method of stabilizing an organic material normally subject to oxide-tire deterioration which comprises adding thereto an inhibitor comprising a monoalkyl ether of a dihydroxy-hydronaphthalene in an amount sufficient to retard said deterioration.

2. A method of stabilizing an organic material normally subject to oxidative deterioration which comprises adding thereto a monoalkyl ether of a 1, i-dihydroxy-5,8edihydronaphthalene. in an amount sumcient to retard said deterioration.

3. A method: of stabilizing an organic material normally subject to oxidative deterioration which comprises adding thereto a monoalkyl ether of a 1,4-dihydroxy-5,6',7,S-tetrahydronaphthalene in an amount sufiicient to retard said deterioration.

4. A method of stabilizing gasoline normally tending to deterioratein storage whichcomprises adding thereto a monoalkyl ether of a 1,4-dihydroxy-5,B-dihydronaphthalene in an amount sutfio ontto tard said deter orati 5. A method of stabilizing gasoline normally tending to deteriorate in storage which comprises adding thereto a monoalkyl ether of a 1,4-dihydroxy 5,6,7,8 tetrahydronaphthalene in an amount suflicient to retard said deterioration.

6. A method of stabilizing cracked gasoline which comprises adding thereto from about 0.001% to about 0.5% by weight of 1-hydroxy-4- ethoxy-5,8-dihydronaphthalene.

7. A method of stabilizing cracked gasoline which comprises adding thereto from about 0.001% to about 0.5% by weight of 1-hydroxy-4- methoxy-5,6,7,8-tetrahydronaphthalene.

8. A method of stabilizing cracked gasoline which comprises adding thereto from about 0.001% to about 0.5% by weight of 1-hydroxy-4- ethoxy-5,6,7,8-tetrahydronaphthalene.

9. A method of stabilizing edible fats and oils normally tending to deteriorate in storage which comprises adding thereto a monoalkyl ether of a 1,4 dihydroxy 5,8 dihydronaphthalene in an amount suflicient to retard said deterioration.

10. A method of stabilizing edible fats and oils normally tending to deteriorate in storage which comprises adding thereto a monoalkyl ether of a 1,4-dihydroxy-5,6,7,S-tetrahydronaphthalene in an amount suflicient to retard said deterioration.

11. A method of stabilizing edible fats and oils against rancidity which comprises adding thereto from about 0.001% to about 0.5% by weight of 1- hydroxy 4 methoxy '7 methyl 5,8 dihydronaphthalene.

12. An organic material normally subject to oxidative deterioration containing, as an inhibitor for said deterioration, a monoalkyl ether of a dihydroxy-hydronaphthalene in an amount sufficient to retard said deterioration.

13. An organic material normally subject to oxidative deterioration in storage containing, as an inhibitor for said deterioration, from about 0.001% to about 0.5% by Weight of a monoalkyl ether of a. 1,4-dihydroxy-5,8-dihydronaphthalene.

14. An organic material normally subject to oxidative deterioration in storage containing, as an inhibitor for said deterioration, from about 0.001% to about 0.5% by Weight of a monoalkyl ether of a 1,4-dihydroxy-5,6,7,8-tetrahydronaphthalene.

15. Cracked gasoline containing from about 10 0.001% to about 0.5% by weight of 1-hydroxy-4- ethoxy-5,S-dihydronaphthalene.

16. Cracked gasoline containing from about 0.001% to about 0.5% by weight of 1-hydroxy-4- methoxy-5,6,7,8tetrahydronaphthalene.

17. Cracked gasoline containing from about 0.001% to about 0.5% by Weight of 1-hydroxy-4- ethoXy-5,6,7,8-tetrahydronaphthalene.

18. Edible fats and oils normally tending to become rancid containing from about 0.001% to about 0.5% by Weight of l-hydroxy-4-methoxy- '7-methy1-5,S-dihydronaphthalene.

19. Edible fats and oils normally tending to become rancid containing from about 0.001% to about 0.5% by weight of 1-hydroxy-4-ethoxy-7- methyl-5,B-dihydronaphthalene.

20. Lard normally tending to become rancid containing from about 0.001% to about 0.5% by Weight of l-hydroxy-4-ethoxy-7methyl-5,8-dihydronaphthalene.

21. An organic material normally subject to oxidative deterioration containing, in suificient amount to retard said deterioration, a monoalkyl ether of a dihydroxy-hydronaphthalene in which said alkyl radical contains from 1 to about 8 carbon atoms.

22. Gasoline normally subject to oxidative deterioration containing, in suflicient amount to retard said deterioration, a monoalkyl ether of a dihydroXy-hydronaphthalene in which said alkyl radical contains from 1 to about 8 carbon atoms.

23. A fatty material normally subject to oxidative deterioration containing, in sufiicient amount to retard said deterioration, a monoalkyl ether 01 a dihydroxy-hydronaphthalene in which said alkyl radical contains from 1 to about 8 carbon atoms.

24. Lard normally subject to oxidative deterioration containing, in sufiicient amount to retard said deterioration, a monoalkyl ether of a dihydroxy-hydronaphthalene in which said alkyl radical contains from 1 to about 8 carbon atoms.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,124,749 Salzberg July 26, 1938 2,363,687 Paul Nov. 28, 1944 2,438,468 Wasson Mar. 23, 1948 

12. AN ORGANIC MATERIAL NORMALLY SUBJECT TO OXIDATIVE DETERIORATION CONTAINING, AS AN INHIBITOR FOR SAID DETERIORATION, A MONOALKYL ETHER OF A DIHYDROXY-HYDRONAPHTHALENE IN AN AMOUNT SUFFICIENT TO RETARD SAID DETERIORATION. 